So McGuire placed her hand on a little black box on the registration desk. A tiny built-in camera beamed infrared light into her palm.

The camera scanned an image of the veins inside McGuire's palm — a signature that's supposed to be as unique as a fingerprint. A computer recorded it in digital code.

Now BayCare, Tampa Bay's largest hospital group, has biometric information that can be used to identify McGuire every time she steps into a BayCare facility. Those include the hospitals of Morton Plant Mease, St. Joseph's, St. Anthony's, and the center McGuire went to, Bardmoor Outpatient & Surgery Center in Largo.

To many people, biometrics still conjure up images from the movies — spies getting retinal scans to enter the secret door.

But the technology is spreading everywhere, from airport security to Walt Disney World, where park visitors get their fingers scanned to enter. A few months ago, students taking the GMAT, the test for business school admissions, began getting their palms scanned to deter cheaters.

BayCare is among the first health care providers stepping into biometrics. A large hospital chain in the Carolinas launched the use of the palm scanners last year. BayCare is the second to use the Patient Secure Identity system, made by Fujitsu Computer Products.

Also in Tampa Bay, a handful of doctors' offices have started using fingerprint scans to identify patients with a device made by a South Florida company, Biometric Technologies Inc.

"For the patient, they don't have to give all their personal information," said Jim Schwamb, BayCare's vice president of patient financial services.

McGuire had never heard of hospitals using biometrics before, but the 21-year-old University of South Florida student was an instant fan.

"It's a really great idea," she said. "It's a really secure way of keeping all my information on file."

Schwamb said patients' worries prompted BayCare to look for a better way to handle busy check-in areas.

"They asked if we could find a way they didn't have to give their Social Security number out as much," he said.

In Charlotte, N.C., about 200,000 patients have enrolled to use palm scans in Carolinas HealthCare System, said spokesman Jim Burke.

The scanners save time and are more accurate than names and numbers for collecting patient records, Burke said.

"Names have lots and lots of spellings," Burke said. "This removes that and becomes the one sure way we know how to identify you."

Hospitals even plan to use the devices to identify unconscious patients who come into the emergency room. That could provide valuable data, such as the patient's medications or whether he or she is diabetic.

"The technology actually works," he said. "It has incredibly good performance, in terms of its accuracy and consistency."

Some biometrics technology, such as facial recognition cameras, has raised privacy concerns. But Becky Steele, regional director of the American Civil Liberties Union in Florida, said she's not worried about the palm technology itself.

"This seems like a good use of technology in that it can be used to make sure patient records can be safeguarded," she said.

Both the palm scans and the fingerprint scans done by Biometric Technologies can cut down on fraud by helping find patients who try to use someone else's name or insurance.

"For the patient, it's preventing medical identity theft," said Scott Kimmel, the company's founder. "For the doctor, they've got the correct patient identified, and we can tie it into an electronic medical record."